1. Field of the Invention
The present invention relates to a duplicating router for duplicating a flat groove, a dovetail groove and the like on a workpiece. The router operates by feeding a cutter unit provided with a motor and cutters such as bit and the like interlocked on a chuck of a horizontal shaft. The cutter unit is fed vertically and horizontally with reference to a base.
2. Background of the Invention
In a woodworking machine, there has been well known hitherto a type provided with a guide plate, which is used to shift a workpiece.
However, since it is difficult for operators to visually ensure a guide plate and a cutter for the workpiece instantaneously and alternately, a large-scale guide apparatus must be used. Thus a conventional woodworking machine becomes large in size as a whole and complicated in structure as well.
A prior art woodworking machine, such as a duplicating router or the like, uses a feed motion wherein a cutter unit is fed vertically and horizontally by a screw feed mechanism. The feed motion depends on a stopper or other means available for shift control of the cutter unit. However, in the case of a duplicating woodworking machine, the fact is that the stopper is not particularly provided as a guide pin is kept creeping along an inner peripheral surface of a duplicating recessed groove and others.
That is, in the duplicating woodworking machine, the guide pin is fed by the screw feed mechanism to the duplicating recessed groove and others for duplicating.
However, in case the guide pin by the screw feed mechanism is fed to the duplicating recessed groove and others merely for duplicating, a high precision will be required for operating a feed screw rod. Also, an unreasonable effect may result on a duplicating part due to excessive turning of the feed screw rod, thus unexpectedly damaging the duplicating part. In case an ordinary working is performed without using the duplicating part, a feed of the cutter unit is capable of causing an erroneous operation, thus degrading the working precision.
A duplicating router has been disclosed by Wirth, Jr. in U.S. Pat. No. 4,593,735. A router with a horizontal shaft and supported on a frame is disclosed by Strong in U.S. Pat. No. 4,163,465.